1. Field of the Invention
The invention herein relates to articles for powering or charging the battery of electronic devices such as cellular telephones, computers and the like from low voltage power sources such as automobile electrical systems or low voltage takeoffs from household electrical wiring.
2. Description of the Prior Art
Numerous electronic devices run on low voltage electrical power, usually battery power. Laptop and palmtop computers, cellular telephones, calculators, compact disk players, radios, and other low voltage devices are all widely known and used. To supplement the battery power in such a device, and to recharge the battery either continually or periodically, one connects the device to a source of electrical power. In many cases the source itself is a low voltage system, such as a vehicle's electrical system, powered from the vehicle's battery and alternator. In other cases the source is a normal household or office 110-volt AC system, which is reduced by an intermediate converter to the low voltage DC used by the device. It is common for manufacturers of such devices to include pre-wired connectors for low voltage connections (usually vehicle connections), or pre-wired converters for household or office electrical system connections, or both, packaged with such devices for sale to the customers/users. Such converters are unitary devices which include a line plug or plug prongs to plug into the 110-volt AC source, e.g, a house or office circuit through a wall socket , the input side of the converter connected to the line plug or prongs directly or through a short length of 2- or 3-wire conductor, and a second 2- or 3-wire conductor connected to the output side of the converter to transmit the low voltage DC power to the device, the second conductor terminating in a second "device-specific" plug configured to be received in a socket built into the device and connecting with the device's internal operating and battery charging circuitry. Similarly, the low voltage connectors are also unitary devices which include a line plug to plug into the 12-volt DC source, e.g, a car's electrical system through the cigarette lighter socket, a second (device-specific) plug configured to be received in a socket built into the device and connecting with the device's internal operating and battery charging circuitry, and a length of 2- or 3-wire conductor to conduct the source power to the device. Since most electronic devices do not operate on 12-volt power, the low voltage connector includes an intermediate resistance circuit to reduce the 12-volt source power to the specific low voltage (&lt;12 V) required by the device. Commonly the resistance circuit and the line plug are constructed as a single unit, with the wire conductor then joining that unit with the second plug.
A typical prior art system of this type is illustrated in FIG. 1. An electronic device, here exemplified by a cellular telephone 2, has a receiving socket 4 for receiving a device-specific plug 6 which is at one end of a 2- or 3-wire conductor 8. At the other end of the conductor 8 is a conventional resistance circuit 10 (inside housing 11), the resistance circuit 10 being connected within housing 11 to a line plug 12, which is configured to connect to a car's electrical system, typically by plugging into the cigarette lighter socket 14 mounted in the car's dashboard 16.
Variations are common. The resistance circuit and its housing 10 can be at an intermediate position of conductor 8, or can be integrated with the device specific plug 6, so that some or all of conductor 8 is disposed between the resistance circuit 10 and the line plug 12. In another alternative, conductor 8, resistance circuit 10 and plug 12 may be permanent parts of the source's structure, such as permanent wiring in a car, and plug 6 may be integrated into a base unit into which the telephone 2 is seated when not in use. Plug 6 will then be structured as part of that base such that seating the telephone in the base unit brings plug 6 and socket 4 into operative contact, so that battery charging of the telephone automatically occurs as needed as long as the telephone is seated in the base.
While such connectors and converters in their various embodiments are widely used, their structure is such that they are less than optimum for convenience and cost effectiveness for most customers and for manufacturers, distributors and retailers of such products. As is evident from the description above, each connector or converter is a unitary device, configured for a specific device and a specific source. Many people own two or more low voltage devices, such as two cellular phones, a phone and a laptop computer, etc. Differences in the structures of the sockets 4 of the various devices are common, since many device manufacturers incorporate their own proprietary socket structures into their products. Consequently, a person who owns a plurality of devices must usually also purchase and use an equivalent plurality of connector or converter products. This is of course costly, but is also inconvenient, since one often finds that he or she has picked up the wrong connector or converter product for the specific device, and that the correct product is elsewhere (e.g. at home instead of in the car, at the office instead of at home, etc.).
In addition, both OEM and after-market manufacturers must produce different connector or converter products for some or all of the electronic devices in their product lines, since the devices may be used with different sources, or the devices may have different socket structures. This is costly for the manufacturer, since additional assembly procedures and worker training, as well as complex inventory and shipping space, control and handling are needed. The likelihood of errors in storing, handling and shipping is also increased.
Further, distributors and retailers also are burdened, since each must order, stock, handle and inventory numerous different connector and converter products. Since a distributor's or retailer's shelf space is finite, and many different kinds of products must compete for that shelf space, the distributor or retailer must limit the number of different connector and convertor products stocked. This of course often leads to lost sales and customer dissatisfaction, when a customer cannot find on the distributor's or retailer's shelf the particular connector or converter product required to fit the customer's specific telephone or other device.
Finally, when a specific telephone or other electronic product is discontinued by its manufacturer, or its electrical configuration is changed in an upgrade or model change, the distributors and retailers usually demand that the OEM or after-market converter or connector product manufacturer take back all of such unsold products and refund the product cost. Such returns and refunds of course are costly for the manufacturer, and in addition the current products are structured such that the return products cannot recycled or reused, at least not in whole, and therefore most or all of each returned product must be discarded, again at substantial cost to the manufacturer.
Some attempts have been made to avoid such deficiencies, but they have been less than satisfactory. For instance, devices have been disclosed in which conductor 8 has been either actually or in effect been forked, i.e., divided into a 2- or more branched Y-shape, each branch terminating in a separate device plug 6 or having each branch terminate in a socket into which a conductor running from a device 2 is plugged. While this does permit more than one device 2 to be used with a single connector or conductor product, all devices must run on identical voltage (or else a plurality of resistance circuits 10 must be used) and the only one device 2 can be used at a time, to avoid current reduction to each device, thus always having present an unwieldy multiplicity of unused branches of the product. Such devices are difficult for manufacturers to produce, and have not been well received by the customers.
It would therefore be of value to manufacturers, distributers, retailers and customers if converter and connector products were available which did not have these technical and economic deficiencies.